Drug Interaction Report

MONITOR: The use of ustekinumab with other immunosuppressive or myelosuppressive agents may increase the risk of infections. Serious bacterial, fungal, and viral infections have been observed during clinical trials with ustekinumab, and the risk may theoretically increase when coadministered with other immunosuppressive therapy. Agents that may be significantly myelo- or immunosuppressive include antineoplastic agents, radiation, zidovudine, linezolid, some antirheumatic agents, high dosages of corticosteroids or adrenocorticotropic agents (greater than 10 mg/day to 1 mg/kg/day, whichever is less, of prednisone or equivalent for more than 2 weeks), and long-term topical or inhaled corticosteroids.

MANAGEMENT: Caution is advised if ustekinumab must be used in patients who have recently received or are receiving treatment with other immunosuppressive or myelosuppressive drugs, and vice versa. Close clinical and laboratory monitoring for the development of severe hematologic adverse effects is recommended both during and after discontinuation of therapy.

Food may have variable effects on the oral bioavailability of zidovudine. Fatty foods have been reported to decrease the rate and extent of zidovudine absorption following oral administration. In a study of 13 AIDS patients, mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of zidovudine were 2.8 and 1.4 times higher, respectively, in fasting patients than in those administered the medication with breakfast. In addition, variations in plasma zidovudine concentrations were increased when administered in the fed state. In another study of eight patients, the time to reach peak concentration (Tmax) was increased from 0.68 to 1.95 hours, and Cmax was reduced by 50% when zidovudine was administered with a liquid high-fat meal relative to fasting. Protein meals can also delay the absorption and reduce the Cmax of zidovudine, although the extent of absorption is not significantly affected. The clinical significance of these alterations, if any, is unknown. The product labeling states that zidovudine may be taken with or without food.